A vacuum vapor deposition apparatus is an apparatus for forming a thin film as follows. First, a deposition target and a vaporization container containing a vaporization material are placed inside a vacuum chamber in the apparatus. Then, while the inside of the vacuum chamber is depressurized, the vaporization container is heated to melt and vaporize the vaporization material through evaporation or sublimation. The vaporized material is then deposited on a surface of the deposition target to thereby form a thin film. As a method of heating the vaporization container, the vacuum vapor deposition apparatus employs methods such as an external heating method using an external heater to heat the vaporization container containing the vaporization material. In recent years, vacuum vapor deposition apparatuses have been used not only to form metal thin films and oxide thin films using metal materials, but also to form organic thin films by depositing organic materials, as well as to form small molecular organic thin films by simultaneously depositing multiple organic materials. For example, vacuum vapor deposition apparatuses are used to form organic electroluminescent elements (hereinafter, referred to as organic EL elements) for flat panel displays.
The vacuum vapor deposition apparatus is also capable of forming a thin film by simultaneously depositing multiple vaporization materials on a substrate or the like (simultaneous deposition). For example, when a luminescent layer is to be formed through a deposition process for an organic EL element, a host material and a luminescent material are used as the vaporization materials. These materials are simultaneously deposited to form the luminescent layer. Thus, information of a luminescent layer, the mixing ratio of a host material and a luminescent material is an important factor that influences the properties of the luminescent layer.